JBL Master Reference Monitor

[sebackman]

Hi

I will post more data tomorrow. A friend has some 2435's and I will try them later. I have 2450SL's, 2451Ti's and 2451Be's and will post data on them in my other thread.



Have a nice Easter.

//RoB

[1audiohack]

That's awesome that you have that/those at your disposal!

[macaroonie]

Someone is having to get by with an old Altec 511 on their M2

I would like to see a rear photo of that horn , curious as to how it is moulded.

[sebackman]

Hi,

Ok, I will post picture of the rear tomorrow.

Kind regards

//RoB

[macaroonie]

Tak

[4313B]

It is amazing that you were able to acquire a pair. JBL was quite adamant about not selling any when the M2 first came out. A couple people at JBL thought they would become available eventually though. I guess this is proof of that.
A few other folks have mentioned that they've been able to get themselves a pair. I'll be using the 476Mg with mine.

[Earl K]

Perhaps (?) this is the correct part .

[Jakob]

Perhaps (?) this is the correct part .

Yes, it has the correct p/n. Is the attaching driver mount flange something one can build yourself you think?

[Earl K]

Yes, it has the correct p/n. Is the attaching driver mount flange something one can build yourself you think?

Thanks .

Questions about attaching a driver to the horn will need to be answered by those who buy this part .

[Don C]

Back-ordered from JBL. I wonder if it's the same story on the cheap 2452 drivers that they show.
Edit: No, they do have the 2452s in stock.

[pos]

http://www.cirmmt.org/activities/wor...toole_workshop
http://mixonline.com/news/news-artic...onitors/424134

For those living in Montreal, a chance to hear Floyd Toole explain the science behind the M2, and then the speakers them-self setup by George Massenburg...

[ivica]

Here is how a 2451Be (Truextent) looks like on the new JBL M2 waveguide. No correction, 1/24 smoothing, short window 4ms

Happy Easter
//RoB

Attachment 65044

HI sebackman,

Thank You for the data You have shown us.
As I know, these are the firs independent measurements of M2 horn with JBL drivers.

Interesting that Your data with 2451Be (Truex) has quite different then POS has shown here (as a D2430K simulated response).
As can be seen that lower frequency horn loading is not amazing even the horn M2 is quite large mouth. I believe that it is because of too fast flaring horn walls, so using under say about 1.5kHz can involve too large diaphragm displacement. Fortunately , Truextent Be suspension is a kind of polymer, but that can be a great danger for using 476Be (JBL original) driver, as its suspension is Be-type, so large diaphragm displacement can break the suspension, (not to mention TAD Be drivers).
An other unexpected behavior is its almost flat response over 3kHz, without expectable -6dB roll-off due to expectable wide (CD) dispersion. When You would show us off-axis responses, may be we can see the total off axis behavior vs frequency.
A kind of dips are visible around 3 and 6 kHz. What would be the result ?

Regards
Ivica

[Lee in Montreal]

Thanks .

Questions about attaching a driver to the horn will need to be answered by those who buy this part .

Looks like someone designed some adapters here. ;-)

http://www.audioheritage.org/vbullet...l=1#post373884

[Flaesh]

http://reconingspeakers.com/product/...lange-5026224/ - M2 Horn Flange #5026224 $96

[pos]

According to Robert that one only fits the D2430K (and maybe 2435?) due to the bolts that fix the adapter to the horn.
See this video at around 00:50 : https://www.youtube.com/watch?v=jDTLZCNzhFQ